04-27-2012, 05:31 AM
That's the right way to do it. First make the O.D. match (unless using cresting, full form inserts), then be certain the pitch of the threads are going to match. Then cut until the pitch diameters match. Done!
If you are using pitch-specific full form inserts, leave the O.D. of the piece .005" to .010" (.12mm to .25mm) oversize. As you machine the thread, watch to see when the cresting insert starts taking some material off the O.D., then you will likely have a match of the two pieces when the O.D.'s match.
Sorry if I made that look easy. I may have a couple of years experience doing it. Until you're well-practiced at it, you can use aids to keep the wires on the threads while you fiddle with the micrometer. Big wires like those used for a 6TPI thread can be stuck on with chewing gum, modeling clay, or with rubber bands to name a few options.
Cheers,
Ken
If you are using pitch-specific full form inserts, leave the O.D. of the piece .005" to .010" (.12mm to .25mm) oversize. As you machine the thread, watch to see when the cresting insert starts taking some material off the O.D., then you will likely have a match of the two pieces when the O.D.'s match.
Sorry if I made that look easy. I may have a couple of years experience doing it. Until you're well-practiced at it, you can use aids to keep the wires on the threads while you fiddle with the micrometer. Big wires like those used for a 6TPI thread can be stuck on with chewing gum, modeling clay, or with rubber bands to name a few options.
Cheers,
Ken